This invention relates to an improvement in an electronic musical instrument of a type wherein multiple waveforms are read out from waveshape memories and are mixed to form a musical tone waveform of a desired tone color.
There has been proposed an electronic musical instrument in which a desired musical tone waveform is produced by reading out, from waveshape memories, sinusoidal waveforms corresponding to respective harmonic components constituting the musical tone and mixing these read out sinusoidal waveforms at suitable relative amplitude levels. If a musical tone containing a large number of harmonic components is to be obtained in this type of instrument, the same number of memories as the number of harmonic components must be provided. This requires a large number of memories resulting in a high manufacturing cost. Besides, since the respective memories are accessed by the same address signal, the number of sample points in one cycle of the sinusoidal wave decreases as the order of the harmonic increases. Accordingly, a large number of sample points is required in the case of a harmonic of a high order in order to maintain a satisfactory waveform and this requires enlarged capacity of the memory.